Timer 555 is wired as an unstable multivibrator. The multi vibrator will work only when water flows through the water tap and complete the circuit connection. It oscillates at about 1 kHz.

2. The working of the circuit is simple. Timer 555 is wired as an unstable
multivibrator. The multi vibrator will work only when water flows
through the water tap and complete the circuit connection. It oscillates at
about 1 kHz. The output of the time at pin 3 is connected to the loud
speaker LS1 via capacitor C3. As soon as water starts flowing through
the tap, the speaker starts sounding, which indicates resumption of water
supply. It remains ‘On’ until you switch of the circuit with switch S1 or
remove the sensor from the tap. The circuit works off a 9V battery
supply.

3. Switch
Step Down Transformer
Resistor-10k,56k
Capacitor-0.01µ,0.01µ,47µ
Water alarm sensor
IC LM555
LS 8 ohm,0.5W speaker

4. STEP DOWN TRANSFORMER:
It is used to decrease the electrical energy that is
form 230v to 9v.As we use only 9v of current for the
circuit.
To convert the current by this transformer we
need 4diodes and capacitor , we can convert it by using
the full wave bridge rectifier.
Resistor:
The resistor is the most common electric component and it
is used to limit and/or control the voltage and current is
an electronic circuit

7. This alarm is for those where is scarcity of water and government supply
water at any tine without any certain management .the state water for
limited duration in a day .This water alarm circuit will save the people
from long wait is it will inform them as soon as the water supply starts .
Timer 555 is wired as a stable Multivibrator . The multivibrator will
work only when water falls through the water tap and completes the
circuit connection . It oscillates at about 1kHz .The o/p of the timer at pin
3 is connected to loudspeaker LS via capacitor c3.As soon as water starts
flowing through the tap ,The speaker starts sounding, which indicates
resumption of water supply . It remains on until you switch off the
circuit with S1 or remove the sensor from the tap. The circuit works off a
9v battery supply.
Connect the lead coming out from the junction of 555pins 2 and 6 to the
body of the water tap Use on/off S1 to power the circuit with the 9v PP3
battery.

9. i. Less expensive
ii. Reduced man power
iii. Low power consumption
iv. Simple and hand efficient